How to count in between gap?

[Michael168]

Let say in A1:A1000, "Dave" have appear a total of 10 times.
How I do count the gap between the times and write
the answer using the row number in other cell of the same row.
But plse remember that "Dave" will appear more than 10 times in the
future.
e.g.
In C1=Dave
In D1=First time
In E1= Second time
and so on until the end.

Thanks
Michael168